Most electronic devices such as servers, computers and the like, are made up of various electronic components within some sort of metal box or chassis. In particular, many servers now fit on individual circuit boards known as “blades” and are placed within a chassis conforming to the Advanced Telecom Computing Architecture (ATCA) 3.0 standard, published January 2003. The ATCA standard defines an open switch fabric-based platform delivering an industry standard high performance, fault tolerant, and scalable solution for next generation telecommunications and data center equipment. The development of the ATCA standard is overseen by the PCI Industrial Computer Manufacturers Group (PICMG)—the same group that created the highly successful Compact PCI standard. The ATCA 3.0 base specification defines the physical and electrical characteristics of an off-the-shelf, modular chassis based on switch fabric connections between hot-swappable blades. Specifically, the ATCA 3.0 base specification defines the frame (rack) and shelf (chassis) form factors, core backplane fabric connectivity, power, cooling, management interfaces, and the electromechanical specification of the ATCA-compliant boards. The ATCA 3.0 base specification also defines a power budget of 200 Watts (W) per slot, enabling high performance servers with multi-processor architectures and multi gigabytes of on-board memory.
During operation, each blade's components generate heat. If the blades are low-power blades, then natural convection may be sufficient to provide adequate cooling to maintain the blades within specified temperatures. If the blades are high-power blades, however, natural convection may not be enough to keep the blades cool and forced convection may be necessary. Existing form factors for low-power blades are not set up to accommodate forced convection, meaning that an upgrade in the blade power usually requires a change of form factor to one that can accommodate forced convection. Existing form factors for high-power blades have substantial forced convection built into them, but it is far more than is needed for low power solution. Because neither form factor is suitable for both high- and low-powered blades the ability to tailor a system to customer requirements is hampered.